Search PubMed⌕ Search

Biomedical subjects

M Silva

Publications and source records attributed to M Silva.

At least 181 records · Page 10Linked to original sources
PubMed1980

Kinetics of IgM and IgG responses in neonatally thymectomized Swiss mice under persistent immunization with sheep red blood cells.

The kinetics of IgM and IgG responses (direct and indirect PCF) in the Swiss mice, neonatally thymectomized, injected three times a week with 5 X 10(8) sheep erythrocytes at the age of two months, were exactly the same as the controls from the same litters. The thymectomized animals showed a statistically significant decrease in both responses (18.6 and 30.2%, respectively). The kinetics of the switch from IgM to IgG and of the latter response inhibition, is the same in both the control and the thymectomized animals.

Animals↗
PubMed1979

[Conditions for greater survival of neonatally thymectomized Swiss mice (author's transl)].

A total of 385 albino Swiss mice, of both sexes, between 24 and 30 hours of age are neonatally thymectomized, by means of a suction pump method. One batch is operated under ether anesthesia, another with sodium pentobarbital, and a third one with Cryoanesthesia. The last batch is subdivided into 2. In one of these the mother is anesthetized with sodium pentobarbital intraperitoneally, during the postoperative recovery of the litter, and in the other the mother is left without treatment. The mothers of the first two batches of thymectomized animals are anesthetized with the same products as their offspring. The percentage of survival of thymectomized breeding mice in greatest in the batch operated under Cryoanesthesia and whose mothers received the above mentioned treatment. Statistically the differences are very significant and they might be accounted to the fact that the mothers are anesthetized while their offspring normalize their physiological constants with better recovery in feeding, hydration, shelter and rest.

Anesthesia, General↗
PubMed1979

The effects of methyl-3-O-methyl gallate on isolated nerve activity.

Methyl-3-O-methyl gallate (M30MG), extracted from Crinodendron hookerianum Gay, decreased both sciatic nerve accommodation and the amplitude of the compound action potential and increased the threshold to rectangular and exponential currents applied to the isolated sciatic nerve in a manner similar to that observed when tetrodotoxin is applied to the nerve. M30MG would act mainly on the large nerve fibres by a mechanism probably resembling that of tetrodotoxin.

Animals↗
PubMed1978

[Influence of temperature and salinity on glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase in mussel (Mytilus edulis, L.) (author's transl)].

The activity of Glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase in mussel hepatopancreas and gill tissues decreases with the salinity of sea water. A decrease in both activities is observed during the first few days in the hepatopancreas of mussel starved at temperatures upper and below the natural thermal habitat; later, the levels of enzymes experience a transitory rise. The influence of temperature on the Km of 6-phosphogluconate dehydrogenase for the hepatopancreas was studied. Minimum value correspond to the nearest temperature to that of the mussel natural habitat.

Animals↗
PubMed1976

On the structure of heparitin sulfates. Analyses of the products formed from heparitin sulfates by two heparitinases and a heparinase from Flavobacterium heparinum.

The analyses of the products formed from heparitin sulfates by the action of two heparitinases and a heparinase from Flavorbacterium heparinum is reported. Heparitin sulfates A and B are degraded by heparitinase I yielding two disaccharides, one of them composed of N-acetylucosamine and an unsaturated uronic, joined by alpha(1 lead to 4) linkage, and the other, with the same composition but with an O-sulfate at the hexosamine moiety. A third disaccharide is also formed from heparitin sulfate B, by the action of the same enzyme, composed of glucosamine N-sulfate and an unsaturated uronic acid joined probably by alpha(1 lead to 4) linkage. Besides these three disaccharides, heparitin sulfate B yields, by the action of heparitinase I, an oligosaccharide (with an average molecular weight of 6000) which is completely degraded by the heparitinase II yielding a disaccharide composed of glucosamine 2,6-disulfate and unsaturated uronic acid. All the disaccharides are further degraded by alpha-glycuronidase from Flavobacterium heparinum yielding the respective monosaccharides. Based on these and other analyses the possible structures of the heparitin sulfates are proposed.

Acetylglucosamine↗